Compression Enhanced Shear Yield Stress of Electrorheological Fluid

Shear tests of an electrorheological fluid with pre-applied electric field and compression along the fleld direction are carried out. The results show that pre-compressions can increase the shear yield stress up to ten times. Under the same external electric field strength, a higher compressive strain corresponds to a larger shear yield stress enhancement but with slight current density decrease, which shows that the particle interaction potentials are not increased by compressions but the compression-induced chain aggregation dominates the shear yield stress improvement. This pre-compression technique might be useful for developing high performance flexible ER or magnetorheological couplings.     

极板形貌修饰对电流变液/极板界面滑移抑制实验研究

被外电场极化而固化的电流变液容易在极板处产生剪切滑移而降低其力学性能.使用抛光、激光打坑、覆盖尼龙网和光刻腐蚀四种方法对极板形貌进行了修饰，并对电流变液的压缩力学性能进行了测试.研究表明，光滑极板和光刻腐蚀柱阵列极板易产生界面滑移而压缩强度较低，粗糙坑阵列和覆盖尼龙网可抑制界面滑移而压缩强度高.极板形貌增强极板附近局部电场强度，强化了链末端与极板间的作用，迫使链结构屈服位置远离链末端，从而有效抑制了滑移.研究结果对进一步认识电流变液的屈服强度，提高电流变器件的力学性能有重要参考价值. 关键词： 电流变液 滑移 极板形貌修饰 压缩应力